Gas turbine engine combustor

Abstract

A gas turbine engine annular combustor (16) has a bulkhead (19) at its upstream end which is protected by an annular array of heatshields (32). Each of the heatshields (32) is spaced apart from the bulkhead (19) by flanges (37, 38,39,40) on the upstream heatshield face. Cooling air entry apertures (47) provided in the bulkhead (19) direct cooling air into the space (36) between the bulkhead (19) and each heatshield (32). The flanges (37,38,39,40) direct the cooling air so that some flows towards a fuel burner aperture (35) in the center of each heatshield (32) while the remainder flows towards the heatshield (32) edges.

I claim: 
     
       1. A gas turbine engine annular combustor including a bulkhead at its upstream end, said bulkhead having a plurality of fuel burner apertures therein, each aperture being adapted to receive a fuel burner, and a plurality of heatshields located on the downstream face of said bulkhead so as to provide thermal shielding thereof, each of said heatshields having edges and being associated with a corresponding one of said fuel burner apertures and itself having a corresponding fuel burner aperture therein, means being provided to space apart each of said heatshields and said bulkhead so that corresponding chambers are defined therebetween, said bulkhead having a plurality of further apertures therein to direct cooling air into each of said chambers, means being provided to subdivide each of said chambers so that a portion of the air operationally delivered to each chamber through said further apertures is directed to flow generally towards said fuel burner aperture of that chamber to be exhausted from said chamber adjacent that fuel burner aperture while the remainder of said cooling air delivered to each chamber through said further apertures is directed away from said fuel burner aperture towards said heatshield edges to be exhausted from said chamber adjacent said edges, means provided adjacent the radially inner and outer edges of each of said heatshields to deflect at least some of the cooling air exhausted from said chamber adjacent said radially inner and outer edges across the downstream face of said heatshield to provide film cooling thereof, seal means located in said corresponding burner apertures in said bulkhead and heatshields to receive fuel burners, means being provided to direct some of the cooling air exhausted from said chambers to provide cooling of said seal means, wherein said means to space apart each of said heatshields and said bulkhead comprises flanges provided on said heatshields, said flanges being connected to said bulkhead, at least some of said flanges constitute said means provided to subdivide each of said chambers, and each of said chambers is sub-divided by an annular flange which is spaced apart from and coaxial with the fuel burner aperture associated with the chamber. 
     
     
       2. A gas turbine engine combustor as claimed in claim 1 wherein further flanges extend between said annular flange and the side edges of each of said heatshields so as to ensure that said remainder of said cooling air operationally delivered to each chamber through said further apertures is directed away from said fuel burner apertures and towards said heatshield edges. 
     
     
       3. A gas turbine engine combustion as claimed in claim 1 wherein each of said heatshields is of generally trapezoidal configuration and abuts circumferentially adjacent heat shields. 
     
     
       4. A gas turbine engine combustor as claimed in claim 1 wherein a portion of said plurality of further apertures is disposed in said bulkhead in a radially inward direction extending toward said fuel burner aperture and a remaining portion of said further apertures are disposed in said bulkhead extending in a direction parallel to a longitudinal axis of said fuel burner aperture. 
     
     
       5. A gas turbine engine combustor as claimed in claim 1, further comprising a plurality of apertures located adjacent said fuel burner aperture in the space between said head shields and said bulkhead to allow exhaustion of cooling air adjacent said fuel burner aperture. 
     
     
       6. A gas turbine engine combustor as claimed in claim 1 wherein the upstream surface of each of said heatshields includes means to enhance the heat exchange relationship between said heatshields and cooling air operationally flowing through said chambers. 
     
     
       7. A gas turbine engine combustor as claimed in claim 6 wherein said means to enhance the heat exchange relationship comprise integral pedestals on each of said upstream surfaces.